Exhaust burners for internal combustion engines



Dec. 10, 1968 v. GUARNASCHELLI 3,415,055

EXHAUST BURNERS FOR INTERNAL'COMBUSTION ENGINES Filed July 24, 1967 W'FIG. 10.

INVENTOR VINCENT GUARNASCHELLI ATTORNE Y United States Patent 3,415,055 EXHAUST BURNERS FOR INTERNAL COMBUSTION ENGINES Vincent Guarnaschelli, Greenlawn, N.Y., assignor to Mutual Industries, Inc., Worcester, Mass., a corporation of Massachusetts Continuation-impart of application Ser. No. 540,614, Apr. 6, 1966. This application July 24, 1967, Ser. No. 655,559

13 Claims. (Cl. 60-49) ABSTRACT OF THE DISCLOSURE A high heat conducting metallic insert positioned inside the exhaust chamber of one or two cylinders (in some constructions two contiguous cylinders exhaust into a common chamber) in a motor block, with the forward end of the insert positioned close to the exhaust valve, where the flaming exhaust meets the insert. The insert provides a partial obstruction to the flow of the exhaust gases and thus momentarily retards or slows them down, giving them additional time to be heated to further combustibility or to maintain their combustible temperature, owing to the very high heat of the insert, rather than permitting them to cool down. Further, owing to the momentary retardation of flow, the trailing richer portion of an exhaust discharge is met by the hotter flaming advance portion of the next subsequent discharge, thereby further enhancing combustion of the said trailing portion.

This application is a continuation-in-part of my application Ser. No. 540,614, filed Apr. 6, 1966, for Means for Burning the Exhaust Gases of Internal Combustion Engines, now Patent No. 3,354,635.

Since the term rectangular is broadly applicable both to a square and to a figure of greater length than width, where rectangular or rectangle is used hereinafter it will be understood to convey the above broad meaning. Further, the term square will be referred to as such or as a square rectangle, and where the term rectangle or rectangular is used to designate a figure of greater length than width it will be termed an elongated rectangle.

Referring briefly to the drawing, FIG. 1 is a fragmentary side elevational view of a motor block, with the exhaust manifold removed, wherein one exhaust outlet chamber is shown having the outline of an elongated rectangle and another is shown as a square rectangle, the former serving to exhaust two contiguous cylinders while the latter exhausts a single cylinder. Also shown are two modifications of the present invention mounted in position.

FIG. 2 is a sectional view taken on the line 22 of FIG. 1, and added thereto in section is the exhaust conduit leading from the exhaust chamber of the single cylinder.

FIG. 3 is a sectional view taken substantially on the line 3-3 of FIG. 1 and added thereto in section is the exhaust conduit leading from the common exhaust chamber of two contiguous cylinders.

FIG. 4 is a sectional view taken on the line 44 of FIG. 2, showing fragmentarily the exhaust manifold as seen looking into the conduits leading from the engine exhaust chambers, with the inserts of the present invention omitted but showing the stop screws therefor.

FIG. 5 is an enlarged perspective view of one form of the insert.

FIG. 6 is an enlarged perspective view of another form of the insert.

FIG. 7 is a top plan view of the insert shown in FIG. 6, with parts broken away and partly in section.

FIG. 8 is a front end elevational view of the insert shown in FIG. 6, viewed along the line 88 of FIG. 7.

FIG. 9 is an exploded side elevational View of the insert shown in FIG. 6.

FIG. 10 is a fragmentary view of the motor block of FIG. 1, showing a modified form of the insert of FIG. 6 registering in the exhaust chamber of a single cylinder.

In internal combustion engines, the exhaust is discharged past the exhaust valve outlet in a flaming condition and the flaming exhaust immediately outside the said outlet is at a very high temperature. Where the exhaust is discharged into an unobstructed conduit, as is the usual condition, the heat of the flame is rapidly dissipated and the exhaust gases are consequently rapidly cooled to a temperature where no further combustion can take place. Thus unburned or incompletely burned pollutants are normally exhausted into the atmosphere. The present invention provides an insert mounted within the exhaust chamber immediately adjacent the exhaust valve outlet, such insert being made of a high heat conducting material. As a consequence of the flaming exhaust engaging the insert, the temperature of the insert is raised to a very high degree, for example, 1800 degrees F. or higher. The exhaust gases pass partly longitudinally through the insert, partly between the chamber walls and the insert, and partly transversely through the insert or parts thereof; the gases thus maintain a very high temperature for continued combustion, with consequent minimizing the escape of pollutants into the atmosphere.

Further, for enhanced combustion of the exhaust gases, a finite though brief interval of time delay is desirable. Such an interval is provided in internal combustion engines (although not normally taken advantage of) between the shutting off of the exhaust valve and its next opening. Where the passage for the exhaust gases is unobstructed for a substantial distance from the exhaust chamber, the said interval is spent in merely permitting the gases to cool. For as the hot gases pass on into the exhaust manifold they are quickly cooled below any possible combustion temperature; in fact, the temperature in the exhaust manifold in even a mild winter climate does not rise above 600' degrees F. In order to further burn the gases it is advisable to provide a retarding obstruction close to the exhaust valve, which obstruction will not only be healed to a very high temperature by the flaming exhaust but will also slow down the average rate of flow of the gases into the manifold and thereby take advantage of the above-mentioned time interval to give the gases time for further combustion.

Continuing this discussion, after explosion of the fuel mixture and its discharge past the exhaust valve, the leading portion of the discharged mass is hotter than the trailing portion whence the latter portion is richer in unburned fuel. Ordinarily, the said trailing portion is discharged into the exhaust manifold in poorly burned condition. With the present invention, however, as the said trailing portion of the discharged mass meets and passes through or by the very hot (1800 degrees F. or higher) insert in the exhaust chamber it is retarded or slowed down for a brief interval. When the leading and hottest portion of the next subsequent explosion meets the said trailing portion of the previous (exhausted) explosion, combustion of the said trailing portion is further enhanced.

Referring in detail to the accompanying drawing, the numeral 15 indicates the top casting of one form of the motor block of an internal combusion engine, above which the spring biased valve stems, not shown, extend,

Merely for the purpose of illustrating the present invention, the casting was selected because it shows both a square exhaust chamber 16 into which a single cylinder discharges and an elongated rectangular chamber 17 into which two contiguous or mutually adjacent cylinders discharge.

FIGS. 2 and 3 show exhaust valves at 18 and 1?, respectively, piston 20, exhaust chambers 16 and 17, respectively, and exhaust manifold conduits Z1 and 22, respectively.

The conduits 21 and 22 lead into the common manifold conduit 50. One form of the insert of the present invention, for a square exhaust chamber 16, consists of a relatively elongated coiled spring 23 made of a high heat conducting material. This spring is substantially circular in cross-section and the turns of the coil may all have the same diameter, substantially as shown, which diameter is substantially equal to the length of a side of the square outline defined by the Walls of the chamber 16, except, possibly, for allowance of sufiicient clearance to permit sliding of the coil into the chamber into, for example, the position thereof shown in FIG. 2. However, the spring may be screwed into such position without clearance since it is subject to a degree of radial compression. The manner of insertion of the spring into the chamber is inconsequential. The pitch of the turns of the coil is preferably sufiicient to permit of some spacing between the turns; in one construction such pitch amounted to about one-sixteenth of an inch. The coil is preferably fitted rather snugly within the chamber 16 and its leading end 24 is preferably positioned as close as possible to the outlet of the valve 18.

To constrain the coil from sliding away from the exhaust valve toward the conduit 21, a stop is provided, preferably in the form of a projection or screw 26 engaging, or adapted to engage, the outer or rear end of the coil. The screw is passed through a threaded opening in the conduit 21, preferably the top wall thereof, as shown.

As the flaming exhaust from the open valve 18 discharges into the chamber 16, part of it will pass longitu dinally through the passage 23 within the hot coil, part will pass through the four corner spaces 27 between the coil and the chamber walls, and other parts will pass radially between the turns of the coil in both directions. In view of the obstruction provided by the coil, the rate of outward fiow of the gases will be retarded, and in view of the high temperature of the coil the slowed down flow of the gases will enable them to be further burned, for the gases will also have been prevented from losing a substantial amount of the heat with which they entered the chamber. During the brief interval of retardation of the flow of the gases, the flaming mass which constitutes the leading portion of the next explosion which is discharged into the chamber meets the richer trailing mass of the previous discharge with consequent enhancement of combustion of the latter, as previously discussed.

In the form of the invention illustrated in FIG. 3 and FIGS. 6-9 and shown mounted in the elongated-rectangular chamber 17 in FIG. 1, the insert 29 is composed of two parts. One part is a relatively elongated housing 30 of elongated-rectangular cross-section having for the greater portion 31 of its length a cross-section complementary to that of the chamber 17. This housing is inserted into the chamber 17 with the said part 31 thereof innermost and close to the outlet of the valve 19, as shown in FIG. 3. The outer or rear end portion 33 has the same height as the portion 31 but has a reduced width, with shoulders 34 on the outside of the opposed side walls of the housing defining the boundary between the two portions 31 and 33.

Grooves 35 extend substantially throughout the length of the housing on the outer surfaces of the top and bottom walls, and grooves 36 extend throughout the length of the opposed side walls of the portion 31 of the housing. Such grooves are preferably rather shallow. The opposed side walls 37 of the reduced portion 33 of the housing have slots 38 cut therethrough.

Within the housing portion 31 and longitudinally near and forward of the shoulders 34, internal shoulders 39 are provided in the opposed side walls thereof, so that the width of the passage 51 through the housing rearward of the shoulders 39 is reduced, as is clear in FIGS. 7 and 8, particularly FIG. 7.

The second part of the insert 29 is a coiled spring 40 of substantially elongated-rectangular cross-section having substantially the cross-sectional dimensions of the reduced passage through the portion 33 of the housing. This spring has substantially the same length as the housing 30, so that although it is contained snugly within the reduced portion of the housing 33, it extends with clearance through the forward portion 31 of the housing, as is clear in FIG. 7.

The assembled insert 29, consisting of the housing 30 and the spring 40, is positioned within the exhaust chamber 17, as shown in FIGS. 1 and 3, preferably with the wider end 32 thereof up close to the exhaust valve outlet. Again, a stop projection or screw 26 is shown extending into the conduit 22 to prevent the housing 3% and the spring 40 from sliding away from the valve outlet.

In use, most of the fiaming exhaust enters the housing through the front end 32; it travels in the direction of the arrow, FIG. 7. Some of this exhaust passes through the longitudinal passage 51 within the spring while some passes between the spring and the interior walls of the housing portion 31; additionally, passage in both radial directions occurs between the turns of the spring. The remainder of the discharged gases, that is, those portions which do not enter the housing 30, pass through the grooves 35 and 36 as well as through whatever clearance space, not shown, may be left between the top wall and the side walls of the housing and the chamber walls. When the exhaust within the housing passes into the reduced end portion 33, some will escape through the slots 38 and then pass on over the outer surface of the housing portion 33. The grooves 35, 36 serve to reduce contact of the housing walls with the walls of the chamber 17, thus reducing heat transference from the housing to the chamber walls.

Since all the parts of the insert 2%, including the housing 311 and the spring are also made of high heat conducting material and, in View of the position thereof close to the flaming exhaust, reach a very high tempera ture, the exhaust gases are efiiciently burned before they enter the exhaust manifold. In this case also, the flow of gases through the chamber 17 is obviously slowed down for a brief interval, giving the gases more time to be burned as well as for the leading flaming portion of the exhaust from the next explosion to engage the trailing, richer portion or" the previous explosion.

FIG. 10 shows a square exhaust chamber 16a for a single cylinder, similar to the chamber 16 of FIG. 1. Instead of using the coil 23 therein, however, an insert 29a, complementarily square in cross section but otherwise similar to the insert 29, is entered into the chamber 16a. For it is Obvious that a square housing 36a and a circular spring 23a may be substituted for the elongatedrectangular housing 30 and an elongated-rectangular spring it in a square chamber 15a. Likewise, if desired, an enlarged elongated-rectangular spring otherwise similar to the spring 46 may be inserted into the chamber 17 without the interposition of the housing 39.

While the inserts 23 and 29 have been illustrated and described as entailing details of construction such as were found effective in a very substantial diminution in the quantity of pollutants exhausted into the atmosphere, obvious modifications may be made without departing from the spirit and scope of the invention. For basically the invention consists in the insertion in the exhaust chambers of a motor block, of a high heat conducting insert, positioned close to the exhaust valve outlet, where the insert serves to become hot enough for combustion of exhausted but unburned fuel and where it further serves to retard the outward flow of the gases with the advantageous results discussed above.

What is claimed is as follows:

1. In combination with the exhaust chamber of at least one cylinder in the motor block of an internal combustion engine wherein said chamber extends outward through the motor block from the exhaust valve of the cylinder and an exhaust conduit leads from said chamber, an elongated high heat conducting insert registering in said chamber, said insert having maximum horizontal and vertical dimensions substantially equal to, respectively, the transverse horizontal and vertical dimensions of said chamber, said insert having a longitudinal passage therethrough, said insert being positioned with one end thereof Within the motor block closely adjacent the outlet from said exhaust valve.

2. A combination according to claim 1, having stop means constraining said insert from moving outward from said exhaust valve outlet.

3. A combination according to claim 2, said stop means comprising a member projecting from a wall of said conduit and positioned adjacent the other end of said insert.

4. A combination according to claim 2, said insert comprising a coiled spring.

5. A combination according to claim 2, said chamber having a cross-section rectangular in outline, said insert comprising a coiled spring.

6. A combination according to claim 5, said crosssectional outline of said chamber comprising a square, said coiled spring being substantially circular in crosssection.

7. A combination according to claim 5, said insert including a tubular housing substantially rectangular in cross-section complementarily to the rectangular outline of said chamber for at least a portion of the length of the housing, said coiled spring having substantially the same length as said housing and registering within said housing.

8. A combination according to claim 7, said crosssectional outline of said chamber comprising an elongated rectangle, said coiled spring being substantially rectangular in outline.

9. A combination according to claim 5, said insert comprising a tubular housing having a first portion of its length substantially rectangular in cross-section complementarily to the rectangular outline of said chamber and having a second portion of its length reduced at least in width.

10. A combination according to claim 9, said housing having internal shoulders dividing said longitudinal passage into a relatively wider portion and a relatively narrower portion, said coiled spring having substantially the same length as said housing and having maximum vertical and horizontal dimensions substantially equal to the vertical and horizontal dimensions, respectively, of said narrower portion of said passage.

11. A combination according to claim 10, said second portion of said housing having slots in the surrounding Wall thereof.

12. A combination according to claim 10', said housing having longitudinal grooves in the surrounding wall thereof.

13. A combination according to claim 10, said rectangular outline of said chamber constituting an elongated rectangle, said longitudinal passage having an elongated rectangular cross-section, said spring having a crosssectional outline substantially complementary to said narrower portion of said passage.

References Cited UNITED STATES PATENTS 2,126,442. 8/1938 Baud 123-145 3,060,678 10/1962 Ridgway -30 3,124,930 3/1964 Powers 60-29 X RALPH D. BLAKESLE-E, Primary Examiner.

U.S. c1. X.R. 123-75, 

